Jurors in the Scott Guy murder trial have been told to think about the possibility of another man killing the Feilding farmer.

Ewen Macdonald is charged with murdering Guy, his brother-in-law, on July 8, 2010 at 4.43am. The Crown says he killed Guy by shooting him in the throat with the farm's shotgun over tensions about the future of the family farm.

He is on trial in the High Court at Wellington.

His lawyer Greg King began his closing address yesterday afternoon, following a four-hour closing by the prosecution. He finished his address after midday today.

King said the 11-member jury needed to think about another man who had a semi-automatic, wore size 12 and had vouchers for Hunting and Fishing.

King said he was not accusing farm worker Simon Asplin of murder, that was not his job, but the jury needed to visualise it.

"He drove a sedan. Matthew Ireland saw a sedan on the way to work then Simon Asplin's sedan turned up at work 15 minutes early.''

King said his semi-automatic gun would make three bangs in quick succession.

"He had attempted to play Scott Guy and Ewen Macdonald off against each other."

Asplin had access to the farm gun and has now been made farm manager, King added.

He asked the jury to consider if it was all co-incidence or all perfectly innocent. But he said looking at it like the Crown did, the jury could paint a sinister picture from it.

The idea that Macdonald was saying Guy had been shot was "ridiculous".

King asked why, if Macdonald had got away with everything else, would he then tell people that Guy' throat had not been cut but rather that he was shot.

Witnesses had not told police about comments from Macdonald until after the police arrested him and it was natural to try to reconstruct conversations, King said.

BOOT EVIDENCE 'FUDGED'

Footprint impressions from dive boots at the murder scene could not have been from the sized boot the Crown alleged Macdonald wore, King said.

"The shoes at the scene, if they are Proline, could not be a size nine."

King said that size of Proline dive boot had 29 wavy lines. The casts found at the scene had more.

"Toe roll is rubbish,'' he told the jury.

The Crown's case, that Macdonald had a pair of Proline boots, began to fall apart when their witness said it might not be that brand, King added.

The casts were more likely to have come from size 11 or 12, King said.

The Crown scientist fudged the evidence by not counting the rows on the dive boots, he added.

King also said Macdonald's dive boots had not been seen since 2008, two years before Guy was killed.

"Not a single witness saw them," King told the jury.

Macdonald's wife admitted during her evidence the questions over the dive boots were doing her head in.

"It's not usually a big deal to throw out an old dive [boot]," King said.

He said Anna Macdonald said it was scungy, tatty, covered in cobwebs, but not at the house they were living in when Guy was shot.

She thought it was thrown out and it was her evidence that she could not remember seeing after she and Ewen Macdonald had moved into the homestead.

'ARGUMENT EXAGGERATED'

A confrontation between Guy and Macdonald at a family event was blown out of all proportion, the jury was told.

King said all Macdonald did at the event was tell Guy that he should not have left others to clean up on the farm.

Macdonald was late to family function because he remained on the farm to help and told Guy about it when he arrived.

"It was Scott that slammed his beer down and walked out,'' King said.

He said other family members attributed the fuss to Guy walking out, not Macdonald's comments.

King read the jury an excerpt from a statement to the police, saying Macdonald spoke to Guy the next day and apologised, saying it was an inappropriate place to bring it up and they went on to talk about their communication.

Macdonald did not go out intending to spoil the family night or later turn that into murderous intent, King said.

He added there was nothing to say that Macdonald knew where the Guy family farm shotgun was. The Crown believed it was used to kill Guy.

King said instead Guy's father Bryan found the gun precisely where he left it and in the two bits he had left it in: "Nothing whatsoever to indicate to him that it had been used or even moved since the last time he saw it."

'NOTHING IN MURDER FOR MACDONALD'

King also told the 11 jurors there was nothing in the murder for Macdonald as he was never going to inherit Guy's portion of the farm.

He said if this was about Guy not pulling his weight on the farm then killing him was not going to fix that.

The jury had heard the shares in the farm went to Kylee Guy and her children after the shooting.

"Killing Scott Guy would also be a crime against his family, and against Anna [Macdonald] and his own children too,'' King said of Macdonald.

He told the jury that whatever Macdonald thought of Guy, there was no evidence he despised his own family enough to leave them with this legacy.

King acknowledged Macdonald had done some horrible things but said it did not make his a murderer.

King went on to tell jurors there was no evidence that so-called poisonous notes intended for Kylee Guy actually existed.

The court was told that malicious letters were left in the Guys' letterbox. They were discovered by the posties, but no action was taken.

King said not a single witness other than the posties ever said they knew about the notes.

"The contradiction about the notes is mindblowing," he said.

The two posties couldn't even be consistent between themselves, even disagreeing on the writing and what was used to write the notes, King said.

"The sad reality is that high profile cases attract people who are seeking publicity,'' he said.

If there were notes they would have been received and Scott or Kylee Guy would have told someone, King said.

Guy, if he found them, never told anyone.

"The notes are rubbish," King said.

ACCUSED ATTEMPTED TO IMPROVE RELATIONSHIP

Macdonald had been trying to put his feelings about Guy behind him and he told his wife Anna that he was going to, King said.

Macdonald took clippings from his own yard for Kylee Guy, bought her a silk tree for her birthday, making steps to move on.

He told the court they were small steps, from his perspective, because if he admitted the arson and vandalism he would lose everything, including his family.

"He was gutless and cowardly and should have owned up to it but he didn't and he instead took these small steps."

King said he knew he had gone completely off the rails with the acts against the Guys' property and was working hard to get himself back on track.

He told the jury lots of people had secrets from their spouses.

"The fact is after that he was getting on better with Scott than they had in years."

There was also positivity about the future of the Guy family farm, not the murderous insecurity the Crown had portrayed, King said.

He disputed there was concern about the farm's future, even after a conference about how to push forward with the farm business.

"Bryan and Jo Guy told you that no decisions had been made and they would all do it together.''

He said instead there was hope of developing alternative revenue streams but even then, "Scott was not going to start digging up the farm for a lake, the next day''.

King added that even with change, Macdonald's life was not confined to the farm and he had alternatives.

"Why would you throw all that away when you have all these other options?"